Before Jessica Ennis-Hill became a mum, the most demanding thing in her life was her sport. But now, the new mum has a rather different set of priorities.

"I’d come home and say, 'The long jump’s gone really bad' and moan to my husband. I can’t do that now because it’s not about me, it’s about Reggie. 'Did he eat all his food today? Did you get that out the freezer? Has he had a poo?' It’s all those really mundane but life-changing things and they’re all priorities now," the 29-year-old from Sheffield told the Telegraph.

Winning gold in the 2012 Olympics for the heptathlon must have been tough – but this year she did it all again winning gold at the World Championships in Beijing in August – just 13 months after giving birth.

"To actually come away with the gold medal a year after having Reggie? I couldn’t believe I’d done it!" she said.

Getting back to fitness was a real challenge for Jess. "You’re used to seeing your body in a certain way and it changes so much," she said. "You’ve got to be patient for it all to come back. Everything’s stretched so much and all your ligaments change."

But it was spending time away from her baby that she found most difficult – her mum or dad would bring Reggie to her training sessions but being separated for the World Championships was painful. "It was so, so hard being the other side of the world," she said. "I just had to stop myself thinking, 'what if something goes wrong or if he’s ill and I’m not there? I can’t get back there really quick.'"

But she insists even the feeling of standing on the podium in Beijing didn't beat becoming a mum. "Nothing for me is greater than the day when Reggie was born," she said. "It was a long day, but having him in our life, you can’t imagine that love that you feel for someone. And it’s strange, because you go to hospital and you come back and there’s this person! They’re essentially like a little stranger, aren’t they? But they’re you and it is an amazing feeling. You’re taken to a whole new world. Everything’s about Reggie."

Now the mum-of-1 is training hard for the Rio Olympics next year – but says she'll retire after 2017, and maybe have more children.